mod = 1000000007
eps = 10**-9
inf = 10**20


def main():
    import sys
    input = sys.stdin.readline

    N, K = map(int, input().split())
    S_list = []
    C = []
    for _ in range(N):
        S, c = input().split()
        S_list.append(S)
        C.append(int(c))

    dp_J = [inf] * (K+1)
    dp_O = [inf] * (K+1)
    dp_I = [inf] * (K+1)
    dp_J[0] = 0
    J_list = []
    O_list = []
    I_list = []
    for S in S_list:
        J_list.append(S.count("J"))
        O_list.append(S.count("O"))
        I_list.append(S.count("I"))
    if sum(J_list) ==0 or sum(O_list) == 0 or sum(I_list) == 0:
        print(-1)
        exit()

    for i in range(K):
        for j in range(N):
            p = J_list[j]
            if not p:
                continue
            c = C[j]
            i_new = i+p
            if i_new < K:
                dp_J[i_new] = min(dp_J[i_new], dp_J[i] + c)
            else:
                cnt = K - i
                S = S_list[j]
                for k in range(len(S)):
                    if S[k] == "J":
                        cnt -= 1
                        if cnt == 0:
                            kk = k
                            break
                cnt = 0
                flg = 0
                for k in range(kk+1, len(S)):
                    if S[k] == "O":
                        cnt += 1
                        if cnt == K:
                            flg = 1
                            kkk = k
                            break
                if not flg:
                    dp_O[cnt] = min(dp_O[cnt], dp_J[i] + c)
                else:
                    cnt = 0
                    for k in range(kkk + 1, len(S)):
                        if S[k] == "I":
                            cnt += 1
                            if cnt == K:
                                break
                    dp_I[cnt] = min(dp_I[cnt], dp_J[i] + c)

    for i in range(K):
        for j in range(N):
            p = O_list[j]
            if not p:
                continue
            c = C[j]
            i_new = i+p
            if i_new < K:
                dp_O[i_new] = min(dp_O[i_new], dp_O[i] + c)
            else:
                cnt = K - i
                S = S_list[j]
                for k in range(len(S)):
                    if S[k] == "O":
                        cnt -= 1
                        if cnt == 0:
                            kk = k
                            break
                cnt = 0
                for k in range(kk+1, len(S)):
                    if S[k] == "I":
                        cnt += 1
                        if cnt == K:
                            break
                dp_I[cnt] = min(dp_I[cnt], dp_O[i] + c)

    for i in range(K):
        for j in range(N):
            p = I_list[j]
            if not p:
                continue
            c = C[j]
            i_new = min(i+p, K)
            dp_I[i_new] = min(dp_I[i_new], dp_I[i] + c)
    print(dp_I[-1])


if __name__ == '__main__':
    main()